This invention relates to a system in which lubricant flows over portions of a scroll compressor which become hot during reverse rotation or loss of charge, heated lubricant passes onto a motor protector, and the motor protector optimizes detection of certain conditions of the heated oil.
Scroll compressors are becoming widely utilized in refrigerant compression applications. In a scroll compressor, a first scroll member has a base and a generally spiral wrap extending from the base. The wrap of the first scroll member interfits with the wrap from a second scroll member. The second scroll member is caused to orbit relative to the first, and refrigerant is entrapped between the scroll wraps. As the second scroll members orbits, the size of the compression chambers which entrap the refrigerant are reduced, and the refrigerant is compressed.
There are certain design challenges with a scroll compressor. As an example, while the scroll compressor efficiently compresses refrigerant when rotated in a proper forward direction, there are undesirable side effects if the scroll compressor is driven to rotate in a reverse direction. Moreover, if the level of refrigerant or charge level being passed through the compressor is lower than expected, there may also be undesirable side effects. Among the many undesirable side effects is an increased heat level at the scroll compressor members.
One safety feature incorporated into most sealed compressors is the use of a motor protector associated with the electric motor for driving the compressor. The same is true in a scroll compressor, wherein a motor protector is typically associated with the stator for the electric motor. The motor protector operates to stop rotation of the motor in the event there is an electrical anomaly, or if the motor protector senses an unusually high temperature. However, the problems mentioned above with regard to reverse rotation and loss of charge typically cause heat to increase at the compressor pump set, which is relatively far from the motor. Thus, it may take an undue length of time for the additional heat being generated in the compressor pump set to pass to the motor protector.
In the disclosed embodiment of this invention, lubricant is caused to flow over a portion of a compressor which becomes hot when adverse conditions are present in the compressor pump set. In the disclosed embodiment of this invention, lubricant is caused to flow over a motor protector of a compressor pump set in sufficient quantities to cause the motor protector to trip the motor and stop further rotation when adverse conditions are present in the compressor pump set. A motor protector is enclosed in a reservoir which allows the heated oil to collect around the motor protector, thereby allowing better heat transfer to the motor protector than if a reservoir were not used. As such, the motor protector will sense an increased temperature much sooner, tripping the motor to stop further rotation of the scroll members.
These and other features can be best understood from the following specification and drawings, the following which is a brief description.